Playing on Creepy Crypts and I fell out of the map.

My character also seems to go downwards whenever I try to move him when I hold left click to move. But hardly became a problem when I just left clicked instead of holding it.
The main problem is when I activated a switch, the door didn't open which it should. I decide to go towards the door and I actually went THROUGH it. Which then fell through the map shortly after.

No choice but to return to camp. Would appreciate if there is an unstuck button.